This is in contrast to a wide array of transcriptomic analyses that report high levels of Snail1 mRNA in a variety of breast cancers, including the breast cancer cell lines analyzed in Fig. 1A. To a certain approximation, the difference between Snail1 mRNA and protein levels can be justified based on the well‐established regulation of Snail1 stability post‐translationally, via phosphorylation, ubiquitin‐mediated degradation, or miRNAs (Díaz and de Herreros, 2016). This evidence concerns the gene SNAI1 and breast cancer.